diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 94132be..dfe5589 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -43,6 +43,10 @@
 ADD_EXECUTABLE(curve_fitting curve_fitting.cc)
 TARGET_LINK_LIBRARIES(curve_fitting ceres)
 
+ADD_EXECUTABLE(curve_fitting_c curve_fitting.c)
+TARGET_LINK_LIBRARIES(curve_fitting_c ceres)
+
+
 ADD_EXECUTABLE(robust_curve_fitting robust_curve_fitting.cc)
 TARGET_LINK_LIBRARIES(robust_curve_fitting ceres)
 
diff --git a/examples/curve_fitting.c b/examples/curve_fitting.c
new file mode 100644
index 0000000..fb75d7d
--- /dev/null
+++ b/examples/curve_fitting.c
@@ -0,0 +1,174 @@
+/* Ceres Solver - A fast non-linear least squares minimizer
+ * Copyright 2013 Google Inc. All rights reserved.
+ * http://code.google.com/p/ceres-solver/
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * - Neither the name of Google Inc. nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without
+ *   specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: mierle@gmail.com (Keir Mierle)
+ *
+ * This is a port of curve_fitting.cc to the minimal C API for Ceres.
+ */
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>  // For NULL
+#include "ceres/c_api.h"
+
+// Data generated using the following octave code.
+//   randn('seed', 23497);
+//   m = 0.3;
+//   c = 0.1;
+//   x=[0:0.075:5];
+//   y = exp(m * x + c);
+//   noise = randn(size(x)) * 0.2;
+//   y_observed = y + noise;
+//   data = [x', y_observed'];
+
+int num_observations = 67;
+double data[] = {
+  0.000000e+00, 1.133898e+00,
+  7.500000e-02, 1.334902e+00,
+  1.500000e-01, 1.213546e+00,
+  2.250000e-01, 1.252016e+00,
+  3.000000e-01, 1.392265e+00,
+  3.750000e-01, 1.314458e+00,
+  4.500000e-01, 1.472541e+00,
+  5.250000e-01, 1.536218e+00,
+  6.000000e-01, 1.355679e+00,
+  6.750000e-01, 1.463566e+00,
+  7.500000e-01, 1.490201e+00,
+  8.250000e-01, 1.658699e+00,
+  9.000000e-01, 1.067574e+00,
+  9.750000e-01, 1.464629e+00,
+  1.050000e+00, 1.402653e+00,
+  1.125000e+00, 1.713141e+00,
+  1.200000e+00, 1.527021e+00,
+  1.275000e+00, 1.702632e+00,
+  1.350000e+00, 1.423899e+00,
+  1.425000e+00, 1.543078e+00,
+  1.500000e+00, 1.664015e+00,
+  1.575000e+00, 1.732484e+00,
+  1.650000e+00, 1.543296e+00,
+  1.725000e+00, 1.959523e+00,
+  1.800000e+00, 1.685132e+00,
+  1.875000e+00, 1.951791e+00,
+  1.950000e+00, 2.095346e+00,
+  2.025000e+00, 2.361460e+00,
+  2.100000e+00, 2.169119e+00,
+  2.175000e+00, 2.061745e+00,
+  2.250000e+00, 2.178641e+00,
+  2.325000e+00, 2.104346e+00,
+  2.400000e+00, 2.584470e+00,
+  2.475000e+00, 1.914158e+00,
+  2.550000e+00, 2.368375e+00,
+  2.625000e+00, 2.686125e+00,
+  2.700000e+00, 2.712395e+00,
+  2.775000e+00, 2.499511e+00,
+  2.850000e+00, 2.558897e+00,
+  2.925000e+00, 2.309154e+00,
+  3.000000e+00, 2.869503e+00,
+  3.075000e+00, 3.116645e+00,
+  3.150000e+00, 3.094907e+00,
+  3.225000e+00, 2.471759e+00,
+  3.300000e+00, 3.017131e+00,
+  3.375000e+00, 3.232381e+00,
+  3.450000e+00, 2.944596e+00,
+  3.525000e+00, 3.385343e+00,
+  3.600000e+00, 3.199826e+00,
+  3.675000e+00, 3.423039e+00,
+  3.750000e+00, 3.621552e+00,
+  3.825000e+00, 3.559255e+00,
+  3.900000e+00, 3.530713e+00,
+  3.975000e+00, 3.561766e+00,
+  4.050000e+00, 3.544574e+00,
+  4.125000e+00, 3.867945e+00,
+  4.200000e+00, 4.049776e+00,
+  4.275000e+00, 3.885601e+00,
+  4.350000e+00, 4.110505e+00,
+  4.425000e+00, 4.345320e+00,
+  4.500000e+00, 4.161241e+00,
+  4.575000e+00, 4.363407e+00,
+  4.650000e+00, 4.161576e+00,
+  4.725000e+00, 4.619728e+00,
+  4.800000e+00, 4.737410e+00,
+  4.875000e+00, 4.727863e+00,
+  4.950000e+00, 4.669206e+00,
+};
+
+/* This is the equivalent of a use-defined CostFunction in the C++ Ceres API.
+ * This is passed as a callback to the Ceres C API, which internally converts
+ * the callback into a CostFunction. */
+int exponential_residual(void* user_data,
+                         double** parameters,
+                         double* residuals,
+                         double** jacobians) {
+  double* measurement = (double*) user_data;
+  double x = measurement[0];
+  double y = measurement[1];
+  double m = parameters[0][0];
+  double c = parameters[1][0];
+
+  residuals[0] = y - exp(m * x + c);
+  if (jacobians == NULL) {
+    return 1;
+  }
+  if (jacobians[0] != NULL) {
+    jacobians[0][0] = - m * exp(m * x + c);  /* dr/dm */
+  }
+  if (jacobians[1] != NULL) {
+    jacobians[1][0] =     - exp(m * x + c);  /* dr/dc */
+  }
+  return 1;
+}
+
+int main(int argc, char** argv) {
+  ceres_init(argc, argv);
+
+  /* Note: Typically it is better to compact m and c into one block,
+   * but in this case use separate blocks for illustration. */
+  double m = 0.0;
+  double c = 0.0;
+  double *parameter_pointers[] = { &m, &c };
+  int parameter_sizes[] = { 1, 1 };
+
+  ceres_problem_t* problem = ceres_create_problem();
+  for (int i = 0; i < num_observations; ++i) {
+    ceres_problem_add_residual_block(
+        problem,
+        exponential_residual,  /* Cost function */
+        NULL,                  /* No loss function */
+        &data[2 * i],          /* Points to the (x,y) measurement */
+        1,                     /* Number of residuals */
+        2,                     /* Number of parameter blocks */
+        parameter_sizes,
+        parameter_pointers);
+  }
+
+  ceres_solve(problem);
+
+  printf("Initial m: 0.0, c: 0.0\n");
+  printf("Final m: %g, c: %g\n", m, c);
+  return 0;
+}
diff --git a/include/ceres/c_api.h b/include/ceres/c_api.h
new file mode 100644
index 0000000..8d74a27
--- /dev/null
+++ b/include/ceres/c_api.h
@@ -0,0 +1,94 @@
+/* Ceres Solver - A fast non-linear least squares minimizer
+ * Copyright 2013 Google Inc. All rights reserved.
+ * http://code.google.com/p/ceres-solver/
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * - Neither the name of Google Inc. nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without
+ *   specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: mierle@gmail.com (Keir Mierle)
+ *
+ * A minimal C API for Ceres. Not all functionality is included. This API is
+ * not intended for clients of Ceres, but is instead intended for easing the
+ * process of binding Ceres to other languages.
+ *
+ * Currently this is a work in progress.
+ */
+
+#ifndef CERES_PUBLIC_C_API_H_
+#define CERES_PUBLIC_C_API_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Init the Ceres private data. Must be called before anything else. */
+void ceres_init();
+
+/* Equivalent to CostFunction::Evaluate() in the C++ API.
+ *
+ * The user is may keep private information inside the opaque user_data object.
+ * The pointer here is the same one passed in the ceres_add_residual_block(). */
+typedef int (*ceres_cost_function_t)(void* user_data,
+                                     double** parameters,
+                                     double* residuals,
+                                     double** jacobians);
+
+/* Equivalent to LossFunction::Evaluate() from the C++ API. */
+typedef int (*ceres_loss_function_t)(void* user_data,
+                                     double squared_norm,
+                                     double out[3]);
+
+/* Equivalent to Problem from the C++ API. */
+struct ceres_problem_s;
+typedef struct ceres_problem_s ceres_problem_t;
+
+struct ceres_residual_block_id_s;
+typedef struct ceres_residual_block_id_s ceres_residual_block_id_t;
+
+/* Create and destroy a problem */
+/* TODO(keir): Add options for the problem. */
+ceres_problem_t* ceres_create_problem();
+void ceres_free_problem(ceres_problem_t* problem);
+
+/* Add a residual block. */
+/* TODO(keir): Add support for loss functions */
+ceres_residual_block_id_t* ceres_problem_add_residual_block(
+    ceres_problem_t* problem,
+    ceres_cost_function_t cost_function,
+    ceres_loss_function_t loss_function,
+    void* user_data,
+    int num_residuals,
+    int num_parameter_blocks,
+    int* parameter_block_sizes,
+    double** parameters);
+
+void ceres_solve(ceres_problem_t* problem);
+
+/* TODO(keir): Figure out a way to pass a config in. */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* CERES_PUBLIC_C_API_H_ */
diff --git a/internal/ceres/CMakeLists.txt b/internal/ceres/CMakeLists.txt
index 549c94e..392d058 100644
--- a/internal/ceres/CMakeLists.txt
+++ b/internal/ceres/CMakeLists.txt
@@ -38,6 +38,7 @@
     block_random_access_sparse_matrix.cc
     block_sparse_matrix.cc
     block_structure.cc
+    c_api.cc
     canonical_views_clustering.cc
     cgnr_solver.cc
     compressed_col_sparse_matrix_utils.cc
diff --git a/internal/ceres/c_api.cc b/internal/ceres/c_api.cc
new file mode 100644
index 0000000..4d7d59b
--- /dev/null
+++ b/internal/ceres/c_api.cc
@@ -0,0 +1,131 @@
+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2013 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+//   this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+//   used to endorse or promote products derived from this software without
+//   specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: mierle@gmail.com (Keir Mierle)
+//
+// An incomplete C API for Ceres.
+//
+// TODO(keir): Figure out why logging does not seem to work.
+
+#include <vector>
+#include <iostream>  // XXX remove me
+#include "ceres/c_api.h"
+#include "ceres/cost_function.h"
+#include "ceres/problem.h"
+#include "ceres/solver.h"
+#include "ceres/types.h"  // for std
+#include "glog/logging.h"
+
+using ceres::Problem;
+
+void ceres_init() {
+  // This is not ideal, but it's not clear what to do if there is no gflags and
+  // no access to command line arguments.
+  google::InitGoogleLogging("<unknown>");
+}
+
+ceres_problem_t* ceres_create_problem() {
+  return reinterpret_cast<ceres_problem_t*>(new Problem);
+}
+
+void ceres_free_problem(ceres_problem_t* problem) {
+  delete reinterpret_cast<Problem*>(problem);
+}
+
+class CallbackCostFunction : public ceres::CostFunction {
+ public:
+  CallbackCostFunction(ceres_cost_function_t cost_function,
+                       void* user_data,
+                       int num_residuals,
+                       int num_parameter_blocks,
+                       int* parameter_block_sizes)
+      : cost_function_(cost_function),
+        user_data_(user_data) {
+    set_num_residuals(num_residuals);
+    for (int i = 0; i < num_parameter_blocks; ++i) {
+      mutable_parameter_block_sizes()->push_back(parameter_block_sizes[i]);
+    }
+  }
+
+  virtual ~CallbackCostFunction() {}
+
+  virtual bool Evaluate(double const* const* parameters,
+                        double* residuals,
+                        double** jacobians) const {
+    return (*cost_function_)(user_data_,
+                             const_cast<double**>(parameters),
+                             residuals,
+                             jacobians);
+  }
+
+ private:
+  ceres_cost_function_t cost_function_;
+  void* user_data_;
+};
+
+ceres_residual_block_id_t* ceres_problem_add_residual_block(
+    ceres_problem_t* problem,
+    ceres_cost_function_t cost_function,
+    ceres_loss_function_t loss_function,
+    void* user_data,
+    int num_residuals,
+    int num_parameter_blocks,
+    int* parameter_block_sizes,
+    double** parameters) {
+  Problem* ceres_problem = reinterpret_cast<Problem*>(problem);
+
+  ceres::CostFunction* callback_cost_function =
+      new CallbackCostFunction(cost_function,
+                               user_data,
+                               num_residuals,
+                               num_parameter_blocks,
+                               parameter_block_sizes);
+
+  std::vector<double*> parameter_blocks(parameters,
+                                        parameters + num_parameter_blocks);
+  return reinterpret_cast<ceres_residual_block_id_t*>(
+      ceres_problem->AddResidualBlock(callback_cost_function,
+                                      NULL, /* Ignore loss for now */
+                                      parameter_blocks));
+}
+
+void ceres_solve(ceres_problem_t* c_problem) {
+  Problem* problem = reinterpret_cast<Problem*>(c_problem);
+  
+  // TODO(keir): Obviously, this way of setting options won't scale or last.
+  // Instead, figure out a way to specify some of the options without
+  // duplicating everything.
+  ceres::Solver::Options options;
+  options.max_num_iterations = 25;
+  options.linear_solver_type = ceres::DENSE_QR;
+  options.minimizer_progress_to_stdout = true;
+
+  ceres::Solver::Summary summary;
+  ceres::Solve(options, problem, &summary);
+  std::cout << summary.FullReport() << "\n";
+}